When the Oni doesn't kill you and instead uses you as a plaything, that's certainly lucky enough that you're even alive...But then she eventually asks you to just live for her and essentially join her?
There really is only one answer in a case like that.

Momiji loves her new husband very much and won't stop showing him how much she appreciates him until her mother orders a time out. Kaede takes Soichiro to a spring in the mountains to relax, but little does he know of its virility boosting effects.